1. Field of the Invention
The present invention relates to a packaging article and corresponding blank component for its manufacture.
2. Description of the Prior Art
U.S. Pat. No. 3,324,214 issued Jun. 6, 1967 to W. A. Schaich describes a process for fabricating what is known to the art as a "bag-in-a-box," Schaich confines a four panel corrugated paperboard sleeve folded from an end-flap enclosed box within a mold structure. Axially through the structurally confined sleeve is drawn an extruded polymer parison. This parison is expanded against the sleeve and removable, top and bottom, mold end plates. Upon removal from the mold, the corrugated box end flaps are closed to provide a fluid-tight, cubically configured, corrugated paperboard container.
U.S. Pat. No. 5,009,039 issued Apr. 23, 1991 to B. A. Goldberg describes a method for fabricating a fluid confining tray having a solid, 0.007 to 0.035 inch thick paperboard sheet substrate blank that is fold erected with corner lapping flaps and confined in pairs within a divided blow mold cavity. A segment of continuously extruded polymer parison tube is clamped and sealed within the cavity by closure of the mold halves. Upon expansion and chilling of the parison segment, the divided mold is opened to release two, oppositely facing tray structures unitized by an unlaminated band of polymer film. The unlaminated polymer band is subsequently trimmed to separate the two-open-top tray products.
As the heat-and-serve markets of prepared and packaged foods have developed for individual and small serving portions, demand has also risen in institutional markets for the same or similar convenience in one to five liter volumes. However, individual serving package structures based upon solid bleached sulphate paperboard have not proven sufficiently strong or rigid to accommodate this institutional market.
It is, therefore, an object of the present invention to provide a fluid tight, composite material tray structure that is sufficiently large and rigid to accommodate a one to five liter volume.
Another object of the present invention is to provide a fluid tight, open top, tray or bowl having corrugated paperboard as a structural substrate base.
Another object of the present invention is to provide a corrugated paperboard substrate for fluid tight, open top, trays or bowls having no lapse or interlocks of the substrate material to cause abrupt, planar discontinuities on the substrate interior surface.